JPS621156B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a double pipeline in which a main pipe of a gas pipe, a water pipe, etc. is inserted into a sheath pipe.

Generally, when burying a conduit across major roads, railroad tracks, rivers, etc., it is not possible to excavate the ground and lay the conduit. In such cases, a construction method called a propulsion construction method is usually used. This construction method involves excavating a working shaft on both sides of a road, etc., and connecting and pushing sheath pipes such as Huyum pipes with a larger diameter than the main pipe one after another from one working shaft toward the other, thereby creating a space between the working shafts. Penetrate. Next, the earth and sand inside the sheath pipe is removed, and the main pipe is inserted into the sheath pipe to form a double pipe.

When forming this double pipe, it is necessary to avoid direct contact between the outer sheath pipe and the inner main pipe as much as possible. If the sheath pipe and the main pipe come into contact, not only will they damage each other, but the contact between the sheath pipe and the main pipe will cause electrolytic corrosion in the double pipe line that has been formed, and the damage will progress rapidly. . Additionally, the sheath pipe cannot always be completely watertight, and water may enter between the sheath pipe and the main pipe through gaps in the sheath pipe during use, causing buoyancy to act on the main pipe. There are things to do. Each time water enters or exits the sheath pipe, gravity and buoyancy act alternately, causing the main pipe to bend and possibly damage it due to fatigue.

In order to prevent such a phenomenon, it is preferable to fit spacers between the sheath pipe and the main pipe at predetermined intervals. This supports the main pipe along the center of the sheath pipe, preventing contact between the main pipe and the sheath pipe, preventing damage to the main pipe and sheath pipe during construction, and preventing electrolytic corrosion even after construction. This also prevents the main pipe from swinging within the sheath pipe due to buoyancy and gravity and damage due to bending fatigue even if water enters the sheath pipe.

However, it is extremely difficult to fit the spacer correctly between the sheath tube and the main tube. After the sheath pipe has been laid, the spacer must be inserted into the sheath pipe at the same time as or before the main pipe is inserted. When inserting into a tube, friction occurs between the spacer and the sheath tube, requiring a large force to insert the main tube, and there is a risk that the sheath tube may be damaged by the spacer. Furthermore, if a problem such as the spacer getting caught in the sheath tube occurs, there is no way to solve the problem. Moreover, it is preferable for the spacer to fit snugly against the inner surface of the sheath tube, but in that case a large force is required when inserting it into the sheath tube, and if a spacer is used that leaves a certain gap, it will not fit inside the sheath tube of the main tube. It is not possible to prevent the rocking of the

The present invention was developed in view of the above circumstances, and uses a very special spacer to carry out the propulsion method, and forms a long double pipe by inserting the main pipe into the sheath pipe with a small force. In addition, each spacer is fitted at a predetermined interval within the formed double pipe line, and each spacer is in close contact with the main pipe and the sheath pipe to reliably prevent the main pipe from swinging. It is possible.

The present invention will be explained below with reference to the drawings. Figure 1 shows an annular tube 1 used as a spacer in the present invention, in which a flexible airtight tube is curved into an annular shape and its both ends are connected. . Pressure fluid is sealed inside it. This annular tube is made by forcing an originally straight tube into an annular shape.
There will be wrinkles inside the ring as shown in FIG. 1, but this will not cause any problem. In this annular tube, the inside and outside of the ring are essentially the same length and are equivalent to each other. Therefore, the inner and outer sides of the ring can be interchanged, and can freely rotate in the circumferential direction of the tube while maintaining the shape of the annular tube.

Now, in order to lay a double pipe line using this annular tube 1, an annular tube 1 is placed on the outer periphery of the main pipe 2.
are fitted, the main tube 2 is inserted into the sheath tube 3, and the annular tube 1 is fitted to the inner periphery of the sheath tube 3. This situation is shown in FIG.

In this state, since the annular tube 1 is inflated by pressure fluid, the main tube 2 is supported by the annular tube 1 along the center of the sheath tube 3, and the two do not come into contact with each other. In FIG. 2, when the main tube 2 is pushed in the direction of arrow A against the sheath tube 3, the inner circumference of the ring of the annular tube 1 is pushed in the direction A together with the main tube 2 due to friction with the main tube 2. The outer periphery does not move due to friction with the sheath tube 3. The annular tube now rolls in the direction of arrow B, allowing the main pipe 2 to move. Therefore, while the main tube 2 is supported along the center of the sheath tube 3 by the annular tube 1, it can freely move in its length direction as the annular tube 1 rolls.

A more specific method of forming a double pipe according to the present invention will be explained with reference to FIG.

A lug-shaped adapter 4 is attached to one end of the sheath tube 3. Reference numeral 5 denotes a flexible auxiliary pipe having a diameter approximately equal to that of the main pipe 2, the tip of which is closed, and a fluid inlet 6 provided at the tip.
A hose 7 is connected to the compressor 9, and the hose 7 passes through the regulator 8, the inside of the sheath pipe 3, and is connected to the compressor 9. A traction wire 10 is attached to the tip of the auxiliary tube 5, and the traction wire 10 passes through the sheath tube 3 and is connected to a winch 11. A plurality of annular tubes 1 are fitted onto the outer periphery of the auxiliary tube 5 at predetermined intervals, and the rear portion of the auxiliary tube 5 is held between nip rollers 12, 12. The auxiliary pipe 5 is then expanded into a cylindrical shape by the pressure fluid sent from the compressor 9. This situation is shown in Figure 3a.

In this state, when the winch 11 is operated and the auxiliary tube 5 is pulled by the wire 10, the auxiliary tube 5 moves forward with the annular tube 1 fitted therein, and the annular tube 1 at the front end comes into contact with the adapter 4. This situation is shown in Figure 3b. When the auxiliary tube 5 is further pulled, the annular tube 1 enters the sheath tube 3 while rolling, and moves forward within the sheath tube 3 while being fitted between the auxiliary tube 5 and the sheath tube 3. Thus, the annular tube 1 fitted into the auxiliary tube 5 enters the sheath tube 3 one after another and rolls. FIG. 3c shows a state in which approximately 1/2 of the auxiliary tube 5 has entered the sheath tube 3. At this time, the annular tube 1 is fitted between the inner surface of the sheath tube 3 and the outer surface of the auxiliary tube 5, and rolls against both, so that the annular tube 1 advances inside the sheath tube 3. The speed is 1/2 of the traveling speed of the auxiliary pipe 5. Therefore, the annular tube 1 is not present in the front half of the auxiliary tube 5 that has entered the sheath tube 3. When the auxiliary tube 5 is drawn into the sheath tube 3 over its entire length as shown in FIG.

Next, place the tip of the auxiliary tube 5 on the nip roller 1.
3 and 13 and connect it to the winder 14. Also, the rear end of the auxiliary pipe 5 is cut and closed, and the discharge pipe 1 is closed.
5 is released into the atmosphere via a regulator 16. The rear end of the auxiliary tube 5 is connected to the tip of the main tube 2, and a plurality of annular tubes 1 are fitted onto the outer periphery of the main tube 2 at predetermined intervals. This state is shown in Figure 3 e.
is shown. When the winder 14 is driven here, the auxiliary pipe 5 is pulled forward, and the main pipe 2 connected to the auxiliary pipe 5 also moves forward. Then, the annular tube 1 fitted into the main pipe 2 enters the sheath pipe 3 as described above, and moves into the sheath pipe 3 at half the speed of the main pipe 2 while rolling.
move forward within. Also, since the annular tube 1 fitted into the auxiliary pipe 5 advances later than the auxiliary pipe 5, the annular tube 1 is separated from the auxiliary pipe 5 to the main pipe 2 as shown in FIG.
to move to. When the main tube 2 is completely drawn into the sheath tube 3 as shown in FIG. 3g, all the annular tubes 1 are fitted between the main tube 2 and the sheath tube 3. Here, auxiliary pipe 5 and adapter 4
By removing this, a double pipe line in which the main pipe 2 is supported by the annular tube 1 inside the sheath pipe 3 as shown in FIG. 3B can be obtained.

Fig. 4 shows an example of a case where sufficient space for construction cannot be secured at the end of the pipe. Pressure fluid is sealed in a short section of the auxiliary pipe 5, and the required number of pipes are placed around the outer circumference of the pipe. An annular tube 1 is fitted (FIG. 4a). The auxiliary tube 5 is then pulled out from the nip rollers 12, 12 and drawn into the sheath tube 3 from its tip. At this time, the annular tube 1 moves forward together with the auxiliary tube 5 at predetermined intervals,
It is fitted between the sheath tube 3 and the auxiliary tube 5 (Fig. 4b, c, d).

Next, the short tube 2' is connected to the rear end of the auxiliary tube 5 in the same manner as in the previous example, and the annular tube 1 is fitted around the outer periphery of the short tube 2' (FIG. 4e). Then, the auxiliary tube 5 is pulled forward, and the short tube 2' is drawn into the sheath tube 3. Once the short tube 2' has been drawn into the sheath tube 3 to some extent, the next short tube 2' is connected to the rear end of the short tube 2' by a method such as welding (Fig. 4f), and this short tube 2' is also drawn into the sheath tube 3. In this way, while connecting the short tubes 2' one after another, they are connected to the sheath tube 3.
Finally, as shown in Figure 4g, the sheath tube 3
A main pipe 2 is formed within which a number of short pipes 2' are connected. In this case, it is not necessarily necessary to fit one annular tube 1 into each short tube 2'. Short tube 2' drawn into sheath tube 3 without fitting annular tube 1
In other cases, two or more annular tubes 1 may be fitted together.In short, it is sufficient that the interval between the annular tubes 1 when the short tubes 2' are connected is a predetermined size.

According to this method, a space corresponding to the length of the main pipe 2 is not required at the end of the sheath pipe 3, and the work can be carried out satisfactorily even in a narrow space.

According to the method of the present invention, when inserting the main pipe 2 into the sheath pipe 3, the main pipe 2 is inserted into the sheath pipe 3 by the annular tube 1.
Since the main tube 2 and the sheath tube 3 are supported along the center of the tube, there is no chance of damage due to contact between the main tube 2 and the sheath tube 3, and the annular tube 1 can roll with almost no resistance, so the main tube can be inserted. The force required for this is extremely small. Moreover, over the entire length of the double pipe line formed by using the auxiliary pipe 5, the main pipe 2
The annular tube 1 is fitted between the sheath tube 3 and the main tube 2, so that the main tube 2 does not come into contact with the sheath tube 3 or swing within the sheath tube 3. Furthermore, even if a large external force is applied to the sheath tube 3, the annular tube 1 absorbs the force, so that the external force does not reach the main tube 2, and the main tube 2 is sufficiently protected.

The annular tube 1 used in the present invention may be formed by connecting airtight rubber or plastic tubes in a ring shape, but it is preferably reinforced by covering the outer periphery with a thin woven fabric.

Although compressed air or water is sufficient as the pressure fluid sealed in this annular tube 1, if a resin liquid (such as urethane) that has reactive hardening properties and is elastic after hardening is used, the main pipe can be sheathed. During the process of inserting into the pipe, the annular tube 1 is in a liquid state and can roll, and by hardening it after forming the double pipe, a permanent spacer can be formed.

Since the annular tube 1 is fitted between the main tube 2 and the sheath tube 3 and rolls, it has a length that is approximately equal to or slightly larger than the inner peripheral length of the sheath tube 3. The outer diameter is the difference between the inner diameter of the sheath pipe and the outer diameter of the main pipe.
It is suitable that tubes approximately equal to 1/2 or slightly larger are connected in a ring.

In addition, when an auxiliary pipe is used, the auxiliary pipe may be a flexible airtight cylinder as shown in the examples shown in Figures 3 and 4, or it may be a rigid pipe similar to the main pipe. . If the auxiliary pipe is a rigid pipe,
It may be an inexpensive material such as vinyl chloride or polyethylene, and does not need to be airtight since it does not need to be inflated with pressurized fluid. If the method shown in FIG. 4 is used, a short auxiliary pipe may be connected and inserted in the same way as the main pipe.

[Brief explanation of the drawing]

FIG. 1 is a front view of an annular tube used in the present invention. FIG. 2 is a longitudinal sectional view showing a state in which the main tube is inserted into the sheath tube. Figures 3 and 4
The figure is a longitudinal sectional view showing the process of the present invention. 1... annular tube, 2... main tube, 3... sheath tube, 5... auxiliary tube.

Claims (1)

[Claims] 1. A main tube is fitted inside the ring of an annular tube in which a flexible airtight tube is curved in an annular shape, both ends of which are connected, and a pressure fluid is sealed therein. The annular tube is inserted into the sheath tube, and the annular tube is fitted inside the sheath tube.The annular tube supports the main tube along the approximate center of the sheath tube, and the main tube is rolled while rolling the annular tube. A method for laying a double pipe line, characterized by moving it in the length direction with respect to a sheath pipe. 2. The method for laying a double pipe line according to claim 1, wherein the outer periphery of the annular tube is reinforced with a thin woven fabric. 3. The method for laying a double pipe line according to claim 1, wherein the pressure fluid is a resin liquid that has reactive hardening properties and has elasticity after hardening. 4 The length of the tube is approximately equal to or slightly larger than the inner circumference length of the sheath tube, and the outer diameter is approximately half the difference between the inner diameter of the sheath tube and the outer diameter of the main tube. A method for laying a double pipe according to claim 1, characterized in that the pipe diameter is equal to or slightly larger. 5. Fit at least one annular tube, which is a flexible airtight tube curved in an annular shape, connecting both ends and sealing a pressure fluid therein, to the outer periphery of the auxiliary tube, and inserting this auxiliary tube from one end of the sheath tube. insert and roll the annular tube, insert the auxiliary tube over almost the entire length of the sheath tube, connect the main tube to the auxiliary tube, and fit at least one annular tube around the outer periphery of the main tube. A method for laying a double pipe line, which comprises: pulling out the auxiliary pipe from the sheath pipe while rolling the annular tube, and inserting the main pipe into the sheath pipe; and inserting the main pipe into the sheath pipe. 6. The method for laying a double pipe line according to claim 5, characterized in that the outer periphery of the annular tube is reinforced with a thin woven fabric. 7. The method for constructing a double pipe line according to claim 5, wherein the pressure fluid is a resin liquid having reaction hardening properties and having elasticity after hardening. 8 The length of the tube is approximately equal to or slightly larger than the inner circumference length of the sheath tube, and the outer diameter is approximately 1/2 the difference between the inner diameter of the sheath tube and the outer diameter of the main tube. A method for laying a double pipe according to claim 5, characterized in that the pipe diameter is equal to or slightly larger. 9. The method for laying a double pipe line according to claim 5, wherein the auxiliary pipe is a rigid pipe whose diameter is approximately equal to that of the main pipe. 10 A patent characterized in that the auxiliary tube is a flexible cylindrical body with a diameter approximately equal to that of the main tube, and is inserted into and pulled out of the sheath tube while enclosing a pressure fluid therein to inflate it into a cylindrical shape. A method for laying a double pipe line according to claim 5.